Effect of selective small molecule inhibitors on MMP-9 and VEGFR-1 expression in p16-positive and -negative squamous cell carcinoma

The identification of molecular targets in the therapy of human papilloma virus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) is a primary aim of cancer research. Matrix metalloproteinase 9 (MMP-9) and vascular endothelial growth factor receptor (VEGFR) have important roles in the development of HNSCC. The tyrosine kinase inhibitors, nilotinib, dasatinib, erlotinib and gefitinib are well established in the targeted therapy of tumors other than HNSCC. The present study aimed to investigate the alteration of MMP-9 and VEGFR-1 expression patterns following treatment with these tyrosine kinase inhibitors in p16-positive and -negative squamous carcinoma cells. MMP-9 and VEGFR-1 expression was evaluated using an ELISA in HNSCC 11A, HNSCC 14C and p16-positive CERV196 tumor cell lines, following treatment with nilotinib, dasatinib, erlotinib and gefitinib. A statistically significant reduction in MMP-9 and VEGFR-1 expression was observed in the p16-negative HNSCC 11A cells following treatment with all inhibitors (P<0.05). VEGFR-1 expression was significantly increased in p16-positive SCC cells following treatment with nilotinib, dasatinib, erlotinib and gefitinib (P<0.05). The expression of MMP-9 and VEGFR-1 was significantly altered by treatment with nilotinib, dasatinib, erlotinib and gefitinib in vitro. The results of the present study are attributed to the efficacy of the tested drugs and present potential compensatory strategies of cancer cells to avoid the antiangiogenic properties of the tested tyrosine kinase inhibitors in vitro.

Tyrosine Hydroxylase Binding to Phospholipid Membranes Prompts Its Amyloid Aggregation and Compromises Bilayer Integrity

Tyrosine hydroxylase (TH), a rate-limiting enzyme in the synthesis of catecholamine neurotransmitters and hormones, binds to negatively charged phospholipid membranes. Binding to both large and giant unilamellar vesicles causes membrane permeabilization, as observed by efflux and influx of fluorescence dyes. Whereas the initial protein-membrane interaction involves the N-terminal tail that constitutes an extension of the regulatory ACT-domain, prolonged membrane binding induces misfolding and self-oligomerization of TH over time as shown by circular dichroism and Thioflavin T fluorescence. The gradual amyloid-like aggregation likely occurs through cross-β interactions involving aggregation-prone motives in the catalytic domains, consistent with the formation of chain and ring-like protofilaments observed by atomic force microscopy in monolayer-bound TH. PC12 cells treated with the neurotoxin 6-hydroxydopamine displayed increased TH levels in the mitochondrial fraction, while incubation of isolated mitochondria with TH led to a decrease in the mitochondrial membrane potential. Furthermore, cell-substrate impedance and viability assays showed that supplementing the culture media with TH compromises cell viability over time. Our results revealed that the disruptive effect of TH on cell membranes may be a cytotoxic and pathogenic factor if the regulation and intracellular stability of TH is compromised.

Comparison of Errors of 35 Weight Estimation Formulae in a Standard Collective

Issue: The estimation of foetal weight is an integral part of prenatal care and obstetric routine. In spite of its known susceptibility to errors in cases of underweight or overweight babies, important obstetric decisions depend on it. In the present contribution we have examined the accuracy and error distribution of 35 weight estimation formulae within the normal weight range of 2500-4000 g. The aim of the study was to identify the weight estimation formulae with the best possible correspondence to the requirements of clinical routine. Materials and Methods: 35 clinically established weight estimation formulae were analysed in 3416 foetuses with weights between 2500 and 4000 g. For this we determined and compared the mean percentage error (MPE), the mean absolute percentage error (MAPE), and the proportions of estimates within the error ranges of 5, 10, 20 and 30 %. In addition, separate regression lines were calculated for the relationship between estimated and actual birth weights for the weight range 2500-4000 g. The formulae were thus examined for possible inhomogeneities. Results: The lowest MPE were achieved with the Hadlock III and V formulae (0.8 %, STW 9.2 % or, respectively, -0.8 %, STW 10.0 %). The lowest absolute error (6.6 %) as well as the most favourable frequency distribution in cases below 5 % and 10 % error (43.9 and 77.5) were seen for the Halaska formula. In graphic representations of the regression lines, 16 formulae revealed a weight overestimation in the lower weight range and an underestimation in the upper range. 14 formulae gave underestimations and merely 5 gave overestimations over the entire tested weight range. Conclusion: The majority of the tested formulae gave underestimations of the actual birth weight over the entire weight range or at least in the upper weight range. This result supports the current strategy of a two-stage weight estimation in which a formula is first chosen after a pre-estimation of the weight range.

High throughput toxicity screening and intracellular detection of nanomaterials

With the growing numbers of nanomaterials (NMs), there is a great demand for rapid and reliable ways of testing NM safety—preferably using in vitro approaches, to avoid the ethical dilemmas associated with animal research. Data are needed for developing intelligent testing strategies for risk assessment of NMs, based on grouping and read‐across approaches. The adoption of high throughput screening (HTS) and high content analysis (HCA) for NM toxicity testing allows the testing of numerous materials at different concentrations and on different types of cells, reduces the effect of inter‐experimental variation, and makes substantial savings in time and cost. HTS/HCA approaches facilitate the classification of key biological indicators of NM‐cell interactions. Validation of in vitroHTS tests is required, taking account of relevance to in vivo results. HTS/HCA approaches are needed to assess dose‐ and time‐dependent toxicity, allowing prediction of in vivo adverse effects. Several HTS/HCA methods are being validated and applied for NM testing in the FP7 project NANoREG, including Label‐free cellular screening of NM uptake, HCA, High throughput flow cytometry, Impedance‐based monitoring, Multiplex analysis of secreted products, and genotoxicity methods—namely High throughput comet assay, High throughput in vitro micronucleus assay, and γH2AX assay. There are several technical challenges with HTS/HCA for NM testing, as toxicity screening needs to be coupled with characterization of NMs in exposure medium prior to the test; possible interference of NMs with HTS/HCA techniques is another concern. Advantages and challenges of HTS/HCA approaches in NM safety are discussed. WIREs Nanomed Nanobiotechnol 2017, 9:e1413. doi: 10.1002/wnan.1413

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Targeted Therapies in HPV-positive and -negative HNSCC - Alteration of EGFR and VEGFR-2 Expression In Vitro

BACKGROUND

Angiogenesis plays a crucial role in the formation and progression of tumor growth in head and neck squamous cell carcinoma (HNSCC). The tyrosine kinase receptors epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) are essential for mediation of pro-angiogenic signals. Nilotinib, dasatinib, erlotinib and gefitinib are tyrosine kinase inhibitors and approved as targeted therapies for several tumor entities other than HNSCC. In this study, we sought to evaluate the alteration of EGFR and VEGFR-2 expression by these tyrosine kinase inhibitors with respect to the human papillomavirus (HPV)-status in squamous cell carcinoma (SCC) tumor cells.

MATERIALS AND METHODS

Expression patterns of EGFR and VEGFR-2 were determined by enzyme linked immunosorbent assay (ELISA) in HNSCC 11A, HNSCC 14C and p-16-positive CERV196 tumor cell lines. These cells were incubated with nilotinib, dasatinib, erlotinib and gefitinib (5-20μmol/l) and compared to a chemonaive control. The incubation time was 24, 48, 72 and 96 h.

RESULTS

All tested substances led to a statistically significant reduction (p<0.05) of EGFR protein expression levels in HPV-negative cells compared to the negative control. Surprisingly, a statistically significant increase in VEGFR-2 expression was observed after exposure to all tested substances especially after exposure to erlotinib treatment.

CONCLUSION

Nilotinib, dasatinib, erlotinib and gefitinib cause significant changes in protein expression of EGFR and VEGFR-2 in vitro. Besides the anti-angiogenic impact of the substances, as shown for the decrease of EGFR expression, we also observed an increase of VEGFR-2 expression. These contradictive effects could be interpreted as a compensatory up-regulation by the tumor cell.

Surface-mediated priming during in vitro generation of monocyte-derived dendritic cells

Ex vivo-generated human dendritic cells (DC) are most commonly generated from monocytes using standard cell culture dishes. To elucidate the effect of the plastic surface during the differentiation process, we compared a standard adhesive plastic dish with four different mainly non-adherent surfaces. Untouched monocytes were cultured for 3 days in the presence of IL-4 and GM-CSF. Time-lapse videos were recorded, and the phenotype of the cells was analysed by flow cytometry. The cytokine profiles were analysed using a 25-plex cytokine assay. The use of non-adherent surfaces led to a significant reduction in expression of CD14 and CD38, and a significant increase in expression of CD86 compared to standard culture dishes. Expression levels of DC-SIGN and PD-L2 were reduced significantly on cells cultured on non-adherent surfaces. The cytokine production was independent on the surface used. The surface-mediated priming should therefore be considered when aiming to induce specific immune responses. This is especially important with regard to DC-based immunotherapy, where an adjustment of the surface during the DC generation process might have highly beneficial effects.

Interleukin 4, interleukin 6 and osteopontin-serological markers of head and neck malignancy in primary diagnostics: A pilot study

The progression of head and neck squamous cell carcinoma (HNSCC) is stimulated by various angiogenic peptides and growth factors. A correlation between tumor progression and the secretion of various serological mediators in patients with malignant tumors of the head and neck is of major interest for tumor diagnostics, evaluation of the therapy response and it may predict prognosis by specifying the individual tumor biology. Established chemotherapeutic regimes for head and neck tumors usually consist of platinum-based chemotherapeutic drugs and 5-fluorouracil (5-FU). The present pilot study sought to assess the eligibility of seven serological factors as biomarkers for malignant tumors of the head and neck: Platelet-derived growth factor, vascular endothelial growth factor, epidermal growth factor receptor, osteopontin, granulocyte-colony stimulating factor, interleukin-4 (IL-4) and IL-6. The serum levels of each factor in 20 patients receiving concomitant radiochemotherapy with cisplatin or carboplatin and 5-FU with curative intent were determined prior and subsequent to chemotherapy and were compared with 40 healthy controls. Another aim of the pilot study was to investigate whether the serum of patients showed significant differences in the concentrations of the analyzed factors at the start of concomitant radiochemotherapy compared with the controls, whether those markers indicated a neoplastic process and whether concomitant radiochemotherapy with cisplatin or carboplatin and 5-FU induced significant alterations of concentration compared with pre-therapeutic levels. The included patients were histopathologically diagnosed with HNSCC and the average age was 62.3 years. The serum samples of the patients were obtained during the course of regular pre- and post-chemotherapeutic blood draws one week prior to the start of radiochemotherapy and one week following the completion of chemotherapy. The healthy controls were collected from patients of the Sleep Laboratory of the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital (Mannheim, Germany) without clinical evidence or laboratory signs of inflammation or history of a malignant disease. The average age was 50.3 years. The serological level of each factor was ascertained by enzyme-linked immunosorbent assay in duplicate. Serum levels of IL-4, IL-6 and osteopontin were significantly increased in patients with HNSCC compared with those in chemotherapy-naive healthy controls. IL-4 and osteopontin showed no significant therapy-associated alterations. Notably, IL-6 levels significantly increased post-therapeutically. Using logistic regression with osteopontin and IL-4, an individual risk-profile for random samples was calculated. IL-4, IL-6 and osteopontin appear to be suitable indicators of the neoplastic process as they are significantly increased in HNSCC patients compared with the control group. With the exception of IL-6, whose levels were in fact increased following therapy, a significant therapy-associated alteration of these factors was missing. Therefore, these serological markers failed to predict the therapy response, but they may be valuable as a screening instrument in primary diagnostics.

Anti-inflammatory effects of polihexanide and polyethylene glycol in an in vitro study in chronic rhinosinusitis

The majority of patients affected by chronic rhinosinusitis (CRS) suffer from eosinophilic infiltration. We hypothesised that polihexanide and polyethylene glycol as an antiseptic might alter the eosinophil-associated IL-5 and eotaxin-3 expression in CRS and also the expression of MMP-9, being involved in the tissue-remodelling in CRS. After obtaining samples from 10 CRS patients with (CRSwNP) and without nasal-polyposis (CRSsNP) and 2 patients with inverted-papilloma undergoing functional endoscopic sinus surgery (FESS), the expression of interleukin-5, eotaxin-3 and MMP-9 were evaluated by an ELISA assay with and without the tested agent. CRSwNP showed a significantly increased expression of IL-5. Polihexanide seems not to alter the attraction of eosinophils in patients with CRS via IL-5 expression. Also elevated levels of MMP-9 could not be reduced to normal values. But there exists statistically significant evidence that the self-amplification process of eosinophils via eotaxin-3 could be influenced by the administration of polihexanide.

Characterization of incidental cardiac masses in oncological patients using a new CT-based tumor volume perfusion technique

Cardiac masses are challenging for non-invasive diagnostic procedures and therapy, respectively. In tumor patients differentiation between primary or secondary cardiac neoplasm and thrombus is a frequent and knowingly difficult task to manage. To avoid complex and unnecessary surgical diagnostic procedures non-invasive methods are in favor. For initiation of adequate therapy and evaluation of prognosis, however, early and reliable diagnosis is mandatory. So far, echocardiography and magnetic resonance imaging represent the mainstay for cardiac imaging diagnosis. Recently, the new technique of CT-based tumor volume perfusion (VPCT) measurement has advanced to a potent, reliable, and easy to perform alternative for cardiac imaging. The purpose of this study was to review the existing spectrum of diagnostic modalities for characterization of cardiac masses in an oncologic patient cohort with emphasis on their strengths and limitations and to present the benefit from using the novel technique called VPCT for this purpose.

Does volume perfusion computed tomography enable differentiation of metastatic and non-metastatic mediastinal lymph nodes in lung cancer patients? A feasibility study

OBJECTIVES

To compare the perfusion characteristics of mediastinal lymph node metastases with those of non-metastatic nodes in patients with newly diagnosed lung cancer using volume perfusion computed tomography (VPCT).

MATERIALS AND METHODS

Between January 2010 and October 2011, 101 patients with histologically confirmed, untreated lung cancer received a 40-s VPCT of the tumor bulk; 32/101 patients had evident hilar/mediastinal metastatic disease and 17/101 patients had proven non-metastasized lymph nodes within the VPCT scan range. Validation or exclusion of metastatic node involvement was proven by mediastinoscopy, biopsy, positron emission tomography imaging and/or unequivocal volume dynamics on follow-up computed tomography. A total of 45 metastases and 23 non-metastatic lymph nodes were found within the scan range and subsequently evaluated. Blood flow (BF), blood volume (BV) and K(trans) were determined. Tumor volume was recorded as whole tumor volume.

RESULTS

In a comparison between metastatic and non-metastatic lymph nodes, we controlled for age, lymph node volume, lung tumor volume, lung tumor location, and histologic type effects and found no significant differences with respect to BF, BV, K(trans) or heterogeneity in nodal perfusion (P > 0.05, respectively), even after adjusting lymph node perfusion values to the perfusion parameters of the primary tumor (P > 0.05, respectively). Metastatic lymph node volume had a significant increasing effect on perfusion heterogeneity (P < 0.05, respectively) and BV in the primary was a highly significant factor for BV in metastatic disease (P < 0.001).

CONCLUSION

Perfusion characteristics of mediastinal metastatic and non-metastatic lymph nodes in untreated lung cancer show considerable overlap, so that a reliable differentiation via VPCT is not possible.

Effective polyethylene glycol passivation for the inhibition of surface interactions of peripheral blood mononuclear cells and platelets

The inhibition of unspecific adhesion of human white blood cells is a prerequisite for applications requiring the control of defined surface interactions. In this study, a passivation agent based on polyethylene glycol (PEG) for glass surfaces was investigated for the use with human peripheral blood mononuclear cells (PBMC). The grafting of 2000 g/mol methoxy-terminated PEG-urea-triethoxysilane (mPEG2000) onto glass surfaces successfully inhibited unspecific spreading of both human PBMC and platelets in all experiments. The prevention of surface interactions was independent on the anticoagulant used during blood collection. The total efficiency to prevent even transient immobilization of PBMC to the PEG modified surfaces was 97 ± 2%. This makes the passivation with PEG a well suited surface modification for preventing unspecific surface interaction in order to study only defined surface interactions of human PBMC.

Unexpected alteration of β-catenin and c-KIT expression by 5-FU and docetaxel in p16-positive squamous cell carcinoma compared to HPV-negative HNSCC cells in vitro

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common type of cancer worldwide. In several tumour entities, the tyrosine kinase receptor c-KIT is associated with tumour transformation in the epithelial tissue in cases of aberrant expression. Furthermore, tumour development and dissemination are a result of dysregulated cellular pathways such as the WNT/β-catenin pathway. β-Catenin is a multifunctional protein within the canonical WNT signalling pathway and a pivotal factor for the stabilization of cell-cell interactions. In malignant tissues, β-catenin triggers tumour proliferation and progression. The aim of this study is to investigate the expression patterns of c-KIT and β-catenin in human papillomavirus-negative and p16-positive SCC and to evaluate the chemosensitivity of the tumour cells to the chemotherapeutical agents docetaxel and 5-fluorouracil (5-FU).

MATERIALS AND METHODS

We incubated the tumour cell lines with docetaxel (5 μmol/ml) and 5-FU (1 μmol/ml) and detected β-catenin and c-KIT by immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) after 48, 72, 120, 192 and 240 h.

RESULTS

We found a reliable trend towards decreased β-catenin expression levels in p16-positive and p16-negative tumour cell lines when incubated with docetaxel, in addition to induced apoptotic effect. At best, 5-FU had a slight influence on the alteration of the expression of β-catenin. Dose escalation of docetaxel and 5-FU had no statistically significant effect on the expression of β-catenin or c-KIT. In HPV-negative HNSCC, a reduced expression level of β-catenin and c-KIT was detected in an incubation period-dependent manner. p16-transformed SCC (CERV196) cells were characterized by a reduced susceptibility to docetaxel induced alteration of β-catenin expression.

CONCLUSION

We were unable to confirm the clinically-substantiated increased chemosensitivity of p16-positive tumour cells in vitro. Extended studies and clinical trials are needed to investigate these findings further in HPV-associated HNSCC.

Chemotherapeutic alteration of VEGF, PDGF and PDGFRα/β expression under 5-FU vs. docetaxel in HPV-transformed squamous cell carcinoma compared to HPV-negative HNSCC in vitro

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the most common malignant epithelial tumor in the upper aerodigestive tract. The incidence of HNSCC induced by the oncogenic human papilloma virus (HPV) is rising, indicating a growing importance of the viral etiology. Cell proliferation, migration and tumor vascularization are regulated by a set of angiogenic peptides such as PDGF (platelet-derived growth factor), PDGFRα/β (platelet-derived growth factor receptor α/β) and VEGF (vascular endothelial growth factor). In locally advanced HNSCC docetaxel is used for induction chemotherapy (ICT) combined with platinum-based chemotherapy and 5-fluorouracil (5-FU). This study sought to evaluate the expression of angiogenic factors (VEGF, PDGF and PDGFRα/β) in HPV-positive (CERV196) and HPV-negative squamous cell carcinoma (HNSCC 11A and 14C) and the efficacy of chemotherapy with docetaxel as a potential treatment modality, compared to 5-FU as a single-drug application.

MATERIALS AND METHODS

Tumor cell lines were incubated with 5-FU or docetaxel at a concentration of 1.0 and 5.0 μmol/ml. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemical analyses were carried out after 48, 72, 120, 192 and 240 hours, in order to identify changes in protein expression of VEGF, PDGF and PDGFRα/β.

RESULTS

We demonstrated a significant reduction of VEGF and PDGFRβ expression after incubation with docetaxel by ELISA and of PDGF by immunohistochemistry, irrespective of the HPV status, whereas the application of 5-FU had a significantly weaker impact on the expression of angiogenic peptides. HPV-positive CERV196 cells were characterized by a reduced susceptibility to a docetaxel-altered expression.

CONCLUSION

Although neither of the applied drugs are selective anti-angiogenic agents, docetaxel surprisingly was demonstrated to cause a significant decrease of angiogenic factors in this study.

Tin-filter enhanced dual-energy-CT: image quality and accuracy of CT numbers in virtual noncontrast imaging

OBJECTIVES

To measure and compare the objective image quality of true noncontrast (TNC) images with virtual noncontrast (VNC) images acquired by tin-filter-enhanced, dual-source, dual-energy computed tomography (DECT) of upper abdomen.

MATERIALS AND METHODS

Sixty-three patients received unenhanced abdominal CT and enhanced abdominal DECT (100/140 kV with tin filter) in portal-venous phase. VNC images were calculated from the DECT datasets using commercially available software. The mean attenuation of relevant tissues and image quality were compared between the TNC and VNC images. Image quality was rated objectively by measuring image noise and the sharpness of object edges using custom-designed software. Measurements were compared using Student two-tailed t-test. Correlation coefficients for tissue attenuation measurements between TNC and VNC were calculated and the relative deviations were illustrated using Bland-Altman plots.

RESULTS

Mean attenuation differences between TNC and VNC (HUTNC - HUVNC) image sets were as follows: right liver lobe -4.94 Hounsfield units (HU), left liver lobe -3.29 HU, vena cava -2.19 HU, spleen -7.46 HU, pancreas 1.29 HU, fat -11.14 HU, aorta 1.29 HU, bone marrow 36.83 HU (all P < .05); right kidney 0.46 HU, left kidney 0.56 HU, vena portae -0.48 HU and muscle -0.62 HU (nonsignificant). Good correlations between VNC and TNC series were observed for liver, vena portae, kidneys, pancreas, muscle and bone marrow (Pearson's correlation coefficient ≥0.75). Mean image noise was significantly higher in TNC images (P < .0001). Measurements of edge sharpness revealed no significant differences between VNC and TNC images (P = .19).

CONCLUSION

The Hounsfield units in VNC images closely resemble TNC images in the majority of the organs of the upper abdomen (kidneys, liver, pancreas). In spleen and fat, Hounsfield numbers in VNC images are tend to be higher than in TNC images. VNC images show a low image noise and satisfactory edge sharpness. Other criteria of image quality and the depiction of certain lesions need to be evaluated additionally.

Mc2 receptor knockdown modulates differentiation and lipid composition in adipocytes

The melanocortin system is involved in central and peripheral regulation of energy homeostasis. In adipocytes, the melanocortin 2 receptor (MC2R) transmits ACTH-dependent signaling and its expression rises substantially during adipocyte differentiation. An in vitro system of retrovirally expressed shRNA directed against Mc2r mRNA in 3T3-L1 cells was established and effects of Mc2r knockdown (kd) in comparison to cells expressing non-targeting shRNA (control) were explored in differentiated adipocytes. Morphology, gene expression, lipolysis and fatty acid composition were analyzed. While gross morphology was unchanged extractable amount of lipids was reduced to 70-80% in kd cell lines (p<0.01). Moreover, expression changes of Pparγ2, aP2, and Pref1 indicated reduced differentiation in Mc2r kd cells. Intriguingly, not only ACTH, but also norepinephrine stimulated lipolysis were substantially reduced demonstrating functional significance of MC2R for general lipolysis pathway. Analysis of fatty acid composition in triglyceride and phospholipid fractions showed a lowered ratio of C16:1/C16:0 and C18:1/C18:0, but increased concentrations of arachidonic acid upon Mc2r knockdown. Reduction of mono-unsaturated fatty acids (MUFAs) was associated with lower expression of stearoyl-Coenzyme A desaturase 1 and 2 in kd cells (21 ± 8% vs. 100 ± 13%, p=0.01 and 32 ± 3% vs. 100 ± 15%, p=0.046). Conversely, high doses of ACTH resulted in gene expression changes, mirroring Mc2r knockdown (higher Pparγ2, Scd1, Hsl expression). MC2R plays an important role for regular lipolytic function and lipid composition in 3T3-L1 adipocytes. Of interest, desaturase expression was reduced and MUFA content accordingly altered in kd cells.

Reduced perfusion in pulmonary infiltrates of high-risk hematologic patients is a possible discriminator of pulmonary angioinvasive mycosis: a pilot volume perfusion computed tomography (VPCT) study

RATIONALE AND OBJECTIVES

The aim of this study was to assess perfusion parameters in atypical pneumonia of heavily immunocompromised hematologic patients suspected of having invasive mycosis using volume perfusion computed tomography and establish their diagnostic role.

MATERIALS AND METHODS

Volume perfusion computed tomographic data from 21 consecutive immunocompromised patients presenting with atypical parenchymal opacity of consolidation were analyzed with respect to the degree of perfusion of their pneumonias. All patients presented with clinical and laboratory signs of infection. Seventeen patients (10 men, seven women; mean age, 57 years; age range, 19-76 years) were found with proven (n = 9), probable (n = 2), or possible (n = 6) angioinvasive mycosis. One patient was diagnosed with bronchoinvasive aspergillosis. Four patients (all men; mean age, 71 years; age range, 67-79 years) were diagnosed with bacterial pneumonia. Volume perfusion computed tomography of the involved pulmonary areas was performed at 80 kV and 60 mAs, with 26 measurement points distributed over 65.9 seconds. Fifty milliliters of contrast material was injected at a rate of 5 mL/s, followed by a 50-mL saline chaser. Entire coverage of the pneumonic parenchymal consolidation was obtained in all patients, with the generation of parametric maps of blood flow (BF) using the maximal slope model and blood volume (BV) using Patlak analysis. The results of perfusion measurements were then analyzed and evaluated for all patients.

RESULTS

Patients with proven, probable, or possible angioinvasive pulmonary fungal infection revealed very low levels of perfusion of their parenchymal consolidations, with BFs ranging from 0.01 to 23.86 mL/100 mL tissue/min and BVs ranging from 0.88 to 10.67 mL/100 mL tissue, lower than those of the adjacent thoracic musculature and of bacterial pneumonias. Bacterial pneumonias showed all increased perfusion parameters, with BFs ranging from 30.49 to 41.65 mL/100 mL tissue/min and BVs ranging from 10.07 to 49.90 mL/100 mL tissue. The cutoff BF value for differentiation was 23.89 mL/100 mL tissue/min, and the cutoff BV value was 9.6 mL/100 mL tissue.

CONCLUSIONS

Patients with angioinvasive pulmonary mycosis showed lower perfusion parameters on volume perfusion computed tomography compared to those experiencing bacterial pneumonia.

Pulmonary lesion assessment: comparison of whole-body hybrid MR/PET and PET/CT imaging--pilot study

PURPOSE

To compare the performance of magnetic resonance (MR)/positron emission tomography (PET) imaging in the staging of lung cancer with that of PET/computed tomography (CT) as the reference standard and to compare the quantification accuracy of a new whole-body MR/PET system with corresponding PET/CT data sets.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. Ten patients in whom bronchial carcinoma was proven or clinically suspected underwent clinically indicated fluorine 18 fluorodeoxyglucose (FDG) PET/CT and, immediately thereafter, whole-body MR/PET imaging with a new hybrid whole-body system (3.0-T MR imager with integrated PET system). Attenuation correction of MR/PET images was segmentation based with fat-water separation. Tumor-to-liver ratios were calculated and compared between PET/CT and MR/PET imaging. Tumor staging on the basis of the PET/CT and MR/PET studies was performed by two readers. Spearman rank correlation was used for comparison of data.

RESULTS

MR/PET imaging provided diagnostic image quality in all patients, with good tumor delineation. Most lesions (nine of 10) showed pronounced FDG uptake. One lesion was morphologically suspicious for malignancy at CT and MR imaging but showed no FDG uptake. MR/PET imaging had higher mean tumor-to-liver ratios than did PET/CT (4.4 ± 2.0 [standard deviation] for PET/CT vs 8.0 ± 3.9 for MR/PET imaging). Significant correlation regarding the tumor-to-liver ratio was found between both imaging units (ρ = 0.93; P < .001). Identical TNM scores based on MR/PET and PET/CT data were found in seven of 10 patients. Differences in T and/or N staging occurred mainly owing to modality-inherent differences in lesion size measurement.

CONCLUSION

MR/PET imaging of the lung is feasible and provides diagnostic image quality in the assessment of pulmonary masses. Similar lesion characterization and tumor stage were found in comparing PET/CT and MR/PET images in most patients.